FFTW++ provides a simple
interface for 1D, 2D, and 3D complex-to-complex, real-to-complex, and
complex-to-real Fast Fourier Transforms that takes care of the technical
aspects of memory allocation, alignment, planning, and wisdom. Wrappers for
multiple 1D transforms are also provided. As with the FFTW3 library,
in-place and out-of-place multithreaded transforms of arbitrary size are
supported.

Implicit dealiasing of standard and centered Hermitian convolutions is
also implemented; in 2D and 3D this implicit zero-padding substantially
reduces memory usage and computation time. See
Efficient Dealiased Convolutions without Padding
by John C. Bowman and Malcolm Roberts, SIAM Journal on Scientific
Computing, 33:1, 386-406 (2011):

Convenient optional shift routines that place the Fourier origin in the logical
center of the domain are provided for centered complex-to-real transforms
in 2D and 3D; see fftw++.h for details.

FFTW++ can also exploit the high-performance
Array class (version
1.47 or higher), designed for scientific computing. The
arrays in that package do memory bounds checking in debugging mode, but can
be optimized by specifying the -DNDEBUG compilation option (1D arrays
optimize completely to pointer operations).

FFTW++ includes interfaces and examples for calling FFTW++ from C++, C,
Python, and Fortran.

Detailed documentation is provided before each class in the fftw++.h header
file. The included examples illustrate how easy it is to use FFTW in C++
with the FFTW++ header class. Use of the Array class is optional, but
encouraged. If for some reason the Array class is not used, memory should
be allocated with ComplexAlign (or doubleAlign) to ensure that the data is
optimally aligned to sizeof(Complex), to enable the SIMD extensions.
The optional alignment check in fftw++.h can be disabled with the
-DNO_CHECK_ALIGN compiler option.

All source files in the FFTW++ project, unless explicitly noted otherwise,
are released under version 3 (or later) of the GNU Lesser General Public
License (see the files LICENSE.LESSER and LICENSE in the top-level source
directory).